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US 5,332,790 AGranted
Liquid-phase fluorination
AssigneeExfluor Research Corporation
InventorsThomas R. Bierschenk, Timothy Juhlke, Hajimu Kawa, Richard J. Lagow
Life of this patent
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Abstract
This invention pertains to a method for liquid phase fluorination for perfluorination of a wide variety of hydrogen-containing compounds.
Claims28
A fluorination method for replacing essentially all of the hydrogen atoms of a hydrogen-containing compound with fluorine atoms, comprising:
- a) continuously introducing said hydrogen-containing compound into a liquid perfluorocarbon, perhalogenated chlorofluorocarbon or chlorofluoroether medium while agitating the medium so that the hydrocarbon-containing compound is dissolved or dispersed within the liquid medium;
- b) introducing fluorine gas diluted with an inert gas into the liquid medium without illumination with ultraviolet light to establish fluorination conditions wherein the liquid medium and fluorine in the vapor space above the liquid medium do not form a flammable mixture at the fluorination conditions, the fluorination conditions being sufficient to replace hydrogen atoms in said hydrogen-containing compound with fluorine atoms;
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- c) continuing the introduction of fluorine gas diluted with an inert gas under the fluorination conditions without illumination with ultraviolet light until essentially all of the hydrogen atoms of the hydrogen-containing compound have been replaced with fluorine atoms without substantial oligomerization and/or polymerization of the hydrogen-containing compound.
1 more element
A method for replacing essentially all of the hydrogen atoms of a hydrogen-containing compound by liquid-phase fluorination, comprising:
- a. providing a perfluorination reactor, wherein the reactor comprises a reaction vessel having means for agitating a liquid contained therein, means for introducing the hydrogen-containing compound into the reactor, means for introducing a gas into the reactor, means for removing a vaporized liquid from the reaction vessel operatively linked to means for condensing the vaporized liquid, and means for returning the condensed liquid to the reaction vessel;
- b. placing a liquid perfluorocarbon, perhalogenated chlorofluorocarbon or chlorofluoroether medium in the reaction vessel;
- c. continuously introducing the hydrogen-containing compound into the reaction vessel while agitating the liquid medium so that the hydrogen-containing compound is dispersed within the liquid medium;
- d. introducing fluorine gas diluted with an inert gas into the reaction vessel without illumination with ultraviolet light to fluorinate the hydrogen-containing compound, the fluorine being diluted so that the liquid perfluorocarbon, perhalogenated chlorofluorocarbon or chlorofluoroether medium and fluorine in a vapor space above the medium do not form a flammable mixture, the amount of fluorine gas being in excess of the stoichiometric amount necessary to replace all of the hydrogen atoms in the hydrogen-containing compound;
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- e. continuing the fluorination reaction without illumination with ultraviolet light until essentially all of the hydrogen atoms of the hydrogen-containing compound are replaced with fluorine atoms without substantial concurrent oligomerization and/or polymerization of the hydrogen-containing compound.
3 more elements
A method for replacing essentially all of the hydrogen atoms of a hydrogen-containing compound with fluorine atoms by liquid-phase fluorination, comprising:
- a. continuously introducing the hydrogen-containing compound into a liquid perfluorocarbon, perhalogenated chlorofluorocarbon or chlorofluoroether medium while agitating the medium so that the hydrogen-containing compound is dissolved or dispersed within the liquid medium;
- b. introducing fluorine gas diluted with an inert gas into the medium without illumination with ultraviolet light to fluorinate the hydrogen-containing compound, the fluorine being diluted so that the liquid perfluorocarbon, perhalogenated chlorofluorocarbon or chlorofluoroether medium and fluorine in a vapor space above the liquid medium do not form a flammable mixture, the amount of fluorine gas being in excess of the stoichiometric amount necessary to replace all of the hydrogen atoms in the hydrogen-containing compound, the fluorine concentration of the gas mixture being of from about 10% to about 40%;
- c. maintaining the fluorination reaction at a temperature of from about -40.degree. C. to about 150.degree. C.;
- d. contacting hydrogen fluoride formed during the fluorination with a hydrogen fluoride scavenger, the amount of hydrogen fluoride scavenger being sufficient to react with the hydrogen fluoride formed during fluorination;
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- e. continuing the fluorination without illumination with ultraviolet light until essentially all of the hydrogen atoms of the hydrogen-containing compound are replaced with fluorine atoms without substantial concurrent oligomerization and/or polymerization of the hydrogen-containing compound.
3 more elements
Dependencies are inferred from the claim text.